Coated fibrous sheet and web material and process for making same



Patented s, 1938 2,129,370

COATED FIBROUS SHEET AND WEB MATE- RIAL AND PROCESS FOR MAKING SAME' Erich Gebauer-Fuelnegg, deceased, late of Evanston, 111., by Marie Gebauer-Fuelnegg, administratrix, Evanston, Ill., and Eugene W. Moffett, Chicago, Ill., assignors to Marbon Corporation, Chicago, 11]., a corporation of Delaware No Drawing. Application December 10, 1936,

Serial No. 115,262

4 Claims. (0]. 91- 68) This application is a continuationin part of my co-pending application, Ser. No. 722,252, filed April 25, 1934. a

This invention relates to coated fibrous sheet and web material for wrapping and other pur poses where a moisture, water, grease and gas resisting material is required.

The diiiiculty with much of the coated sheet and web material, previously proposed for this solution of rubber in benzene, carbon tetrachloride or other volatile solvent.

The rubber hydrochloride preferably should not be entirely reacted with hydrogen chloride where flexibility is particularly important, but the reaction should be stopped at some intermediate point, say at a point where the chlorine content of the rubber is about 24% by weight. The exact percentage is not critical but it should be suiliciently low so that the rubber compound does not become brittle but retains suflicient stretchability that the film will not break when the fibrous base material is folded. When the chlorine content exceeds 24%,the rubber compound is likely to be insuiiiciently flexible and elastic. If the rubber is insufliciently reacted with hydrogen chloride, however, the product will be tacky and for that reason unsuitable for use. Any rubber sufliciently reacted to be non-tacky the arochlors (chlorinated diphenyls), paraflin, chlorinated paraflin, polycumarcne, rosin and dammar gum. Various antioxidants may also be added to preserve the rubber if desired.

The following formula of a satisfactory coating composition is not to be construed as a limitation on the invention since the proportions are not critical, but is to be understood as givin desirable proportions ,which have been found to be operative.

purpose has been that the coating cracks when is usable. the paper is bent or scored, and the material The exact minimum chlorine content which thus loses much of its efliciency as an impervious will result in a rubber hydrochloride which is wrapper or container. In the present invention non-tacky at ordinary room temperature varies the fibrous base is coated with a thin layer of a slightly according to the type ofrubber hydro- 15 compound of rubber formed by reacting rubber chloride. In general, rubber hydrochlorides haveither partially or completely with a hydrogen ing a chlorine content of about 28% and above halide by any suitable process. are non-tacky, and satisfactory for coating on It is, therefore, an object of this invention to paper to obtain a sheet usable for wrapping purprovide a fibrous web or sheet base treated with poses, although the coating produced is not as rubber hydrohalide. flexible as that obtained by coating with rubber It is a further object of this invention to prohydrochlorides having a chlorine content of 24% vide a process for preparing a rubber hydrochloby weight. ride coated or impregnated fibrous web or sheet If a comparatively heavy paper or fiber board material that is highly resistant to the penetrais to be coated, the film of rubber compound 25 tion of moisture, water, grease or gases. should be more flexible and, therefore, have a b Other and further objects of this invention low chlorine content in order to avoid breaking will be evident from the following specifications of the coating when the paper is folded. and the accompanying claims. The rubber hydrochloride is dissolved in any The rubber hydrohalide used in this process suitable solvent such as carbon tetrachloride, may be produced by the method disclosed in our benzene and its homo ogu s, 0 ethylene d oapplication Serial No. 703,866, now Patent d P erably to a concentration of 8 to 10%. #1380396, In this process, unvulcanized ruband in general betwe n 4 and 12% y w i h her, in sheet or comminuted form, is exposed to A satisfaetbl'y COB-ting p s ti can be the action of a hydrogen halide, such as hydrom de y t above procedure. but it is P e a e gen chloride, either in gaseous form under preso dd 3 gm resin to 8 38 a bonding g tsure or in liquefied condition. When the rea Such substances cause a firmer adherence of the tion is partially or substantially complete the coating to the fibrous base a y b used in reaction product is isolated. amounts up to 75% of the dry solids contained By stopping before the reaction is complete; in the coating solution. The use of various gums 40 a Pa y reacted P t p c ally suitable for or resins in this manner is also advantageous use the Present invention y readily be since the viscosity of the solution is somewhat 53% d t d th t th thod reduced by 8 tin 81's 00 a 0 er me 5 may various 1- sins also be used for making the rubber hydrohalide. been to be mz f gf igggz such as passing hydrogen chloride through a Example Percentage by weight Rubber hydrochloride 30-75 Chlorinated diphenyl -25 The coating solution may comprise a solution of about 8 to 10% by weight of the above mixture in a suitable solvent.

This coating material may be used advantageously on a number of types of paper including grease proof papers and hard surfaced relatively transparent cellulosic material such as parchment, glassine, regenerated cellulose and other papers to give a transparent, coated sheet material. If high transparency is desired, it is preferable to use a rubber hydrochloride prepared by treatment of rubber with liquid hydrogen chloride at low temperatures such as -85 C. or by reaction between rubber in a solvent and gaseous hydrogen chloride at low temperatures, since these methods produce a rubber hydrochloride capable oi forming a highly I transparent film. Opaque papers made'from chemical wood pulp and fibre boards may be coated with less transparent films of rubber hydrochloride. Many types of papers used as wrapping materials may be advantageously made moisture resistant by a coat ing of this composition.

The coating may be applied to one or both sides of the fibrous base material in a continuous manner, as by a fountain roll, doctor or the like, in a tower coater, or in a straight pass air floated type of coating machine. In general, the coating two sheets of the material are pressed together,

and heated, a secure bond between them is formed. This makes it possible to use paper which has been coated with this composition in wrapping machines in a similar manner to waxed paper. It is preferable to waxed paper, in fact, since when waxed paper is sealed in this manner the bond is much weaker than when the material disclosed herein is used.

Our coating has the advantage of being tacky at ordinary room temperatures and renonsistant to the passage of grease, gas, moisture, and water, thus making an ideal wrapping material Coated fiber board, for instance, is admirably suited for making up into containers for food products, such as iroaen foods, tats, butter, coflee and the like. Laminated material may also be prepared with our composition as the adhesive layer.

Where the term "rubber is used herein and in the claims, it will be understood to mean rubber, caoutchouc, and rubber-like materials, either natural or synthetic in their origin, including balata, gutta percha and chicle.

We are aware that numerous details or the process may be varied through a wide range without departing from the principles of this invention, and we, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

We claim:

1. Sheet material suitabletorwrappingpurpooes and the like, and characterized by being heat sealing, transparent, and highly resistant to moisture vapor, comprising a regenerated cellulose sheet having a coating thereon composed essentially of a rubber hydrochloride and a chlorinated diphenyl.

2. Sheet suitable for wrapping purposes and the like, characterized by being heat sealing, transparent, and highly resistant to moisture vapor, comprising a regenerated cellulose sheet having a coating thereon composed essentially of a rubber hydrochloride and one or more substances from the group of waxes and resins consisting of paraffin wax, chlorinated diphenyls, polycoumarone, rosin and dammar.

3. Sheet suitable for wrapping purposes and the like, characterized by being heat sealing, transparent, and highly resistant to moisture vapor, comprising a regenerated cellulose sheet having a coating thereon composed essentially of a rubber hydrochloride and parailln wax.

4. Sheet suitable for wrapping purposes and the like, characterized by being heat sealing, transparent, and highly resistant to moisture vapor, comprising a regenerated cellulose sheet having a coating thereon composed essentially of a rubber hydrochloride and a polycoumarone.

MARIE GEBAUER-FUEINEGG, Administratrix of the Estate of Erich Gebauer- Fuelnew, Deceased.

EUGENE W. MOFFE'I'I. 

